Means for treating lubricants



Oct. 24, 1961 F. M. BOSWORTH MEANS FOR TREATING LUBRICANTS Filed Feb. 9.1955 INVENTOR. 'FEEDEE/C N-BOS'WOWH %,IM,; Mn 1- M ATTORNEYS 11 tan Thisinvention relates to neutralizing acids in the lubricating oil ofinternal combustion engines, removing the acid salts as well as theacids from the engine oil, and preserving the oil and the engine fromthe deleterious incidents and effects of acids and/or acid salts orcompounds found or formed therein.

The deleterious incidents and effects of acids formed in internalcombustion engines which contaminate and are carried by the lubricatingoil and/or water content thereof has been largely appreciated, and arebelieved to manifest themselves in etching and corroding wearing andbearing surfaces forming or tending to form sludge and varnishes in theoil, varnishing wearing and bearing surfaces and otherwise hamperinglubrication, augmenting engine wear and deterioration, reducing enginelife and impairing engine performance.

Liquid or suspended alkaline oil additives, while tending to neutralizesuch acids, tend in themselves to subtract or detract, pro tanto, fromthe lubricating value of the oil, and the acid salts or residuum formedin the oil are not desirable lubricants. Moreover, it is difficult toapportion or maintain an optimum quantity of liquid neutralizingadditive in the oil, since none would be best from the point of View oflubrication, and therefore the last alkaline molecule would be theoptimum quantity in that sense, wherefore the spending of that moleculewould require the addition of another, and so on. The employment ofmetal, such as magnesium, in solid form in the crankcase of engines hasbeen practiced not, it is believed, without benefit. But this approachhas been burdened with limitations. Metallic acid salts retained on thesurface of the metal impair its efficiency while those washed or lostfrom the surface may enter the oil pump and circulate with the oil tothe hazard and detriment of the pump and engine. Moreover, dirt, sludgeor other substances foreign to the magnesiurn metal tend to collect onor obscure its surface and impair, restrict or forbid its intendedfunction.

An object of my invention is to provide a solution to the problemsmentioned above that can be practiced and enjoyed with advantage,efficiency, economy and facility. Another object is to provide an acidhungry, expendable metal in a form, time and place in the engine oilsystem and cycle of circulation that will for relatively long periods oftime offer a large, clean, and/or selfcleaning, active metal surface tobe etched or consumed by the acids carried in the oil, whereby toneutralize and remove the acids. Another and concurrent object is totrap out from and free the oil, oil pump and engine from the metal acidsalts or other residuum created by the metal acid reaction substantiallysimultaneously with the reactions. Another object is to free the oilfrom liquid or suspended alkaline additives and the need therefor.Another object is to provide a continuous surplus of neutralizing agentfreely available at all times to the oil and acid borne or entrainedtherein without diluting the oil therewith. Another object is tofacilitate the easy provision, inspection and replacement of theneutralizing agent. A further object is to provide an acid hungry metalin a form with a great ratio of surface to volume and with a largesurface area exposed in and to the moving oil stream of the engine withcorrespondingly great opportunity for the oil-borne acids to be spent inetching or reacting with the metal.

Patented Get. 24, 1961 More specifically my objects include theprovision of a large, thin, perforate acid neutralizing sheet ofmagnesium, magnesium alloy, zinc or other acid-hungry metal of size andthickness permitting flexing or bending for insertion in the engine-oilfilter interiorly of the filter shell and exteriorly of the filterelement whereby the acid-bearing oil will wash or flow over and/ orthrough and around the metallic sheet, and the acid-metal salts,residuum and/ or erroded or corroded parts or particles of the expendedsheet will be filtered out of the oil stream in and by the closelyadjacent filter element. It is also among my objects to encompass inwhole or in part a permanent or replaceable filter element or cartridgewith acid-hungry metal or materials in a form or shape not tending todeleteriously impair the flow of oil through the filter element orcartridge, but offering a great or sufficient surface area to oilentrained acids for facile reaction therewith.

Another object is to dispose acid-hungry metal of great surface area inthe oil stream of an acid forming engine at a place where the stream isgiven wide, thin form coextensive with the wide surface area of thereactant metal wherewith to gain a wide and extensive contact betweenthe oil and the reactant metal and to use the motion of the thin streamto promote reaction and opportunity for reaction between the oilentrained acids and the metal. It is a collateral object that the oilstream and/or the thinness and velocity thereof tend to work or scrubthe acid reactant metal surface tending to clean the same and maintainreactant metal exposed or freshly exposed and reactantly available tooil entrained acids.

Other objects and advantages of my invention will appear from thefollowing description of preferred and modified forms thereof, referencebeing had to the accompanying drawings in which:

FIGURE 1 is a perspective view of an oil filter with the shell and coverpartly broken away showing the acid neutralizing, expendable metallicsheet disposed between the shell and filter element FIGURE 2 ishorizontal section taken along the lines 2-2 of FIGURE 1.

FIGURE 3 is an elevation of one side izing sheet in flat form.

FIGURE 4 is a section line 44 of FIGURE 3.

FIGURE 5 is a diagrammatic perspective on reduced scale of theneutralizing sheet and filter element arranged with the long axis of thesheet parallel with the axis of the element, of. FIGURE 1.

In FIGURE 1 a conventional form of automobile engine filter P, which maybe taken as illustrative of various forms, comprises a shell 1 and aremovable cover 2 secured to the shell by a bolt 3; the shell having anoil inlet 4 and an oil outlet 5. Within the shell and radially spacedfrom the interior of the shell is the filter element 6 through which theoil is constrained to pass in its flow from the inlet 4 to the outlet 5.The expendable acid-hungry metal 13, preferably in perforate sheet formis curved to lie freely between the shell and the element, see FIGURE 2,and is preferably disposed near the inlet t to be washed in the streamof oil entering the shell and flowing longitudinally andcircumferentially of the filter element and in the directions of themajor dimensions of the sheet wherewith to expose a great wide surfacearea to the oil-entrained acids and promote reaction therewith.

Conventionally the filter element 6 has fluid impervious upper and lowerend closures, the upper closure 7 along being shown in part in FIGURE 1,and presents a cylindrical exterior surface or superficial surfacejuxtaof the neutralof the sheet taken along the v 8 opposite or near theand advantageous to ing the external posed to the interior of the shelland spaced therefrom describing an annular space 8, see also FIGURE 2,between the interior of the shell and the exterior of the element. It isillustrative of the operation of conventional oil filters compatiblewith my invention that the dirty oil entering the shell through theinlet 4 flows longitudinally and circumferentially of the space 8 andradially through the filter element to the central core or passage 9thereof thence axially to the outlet 5; the passage 9 beingappropriately sealed off from the space 8 according to known practice. Ispeak of the superficial external pervious surface of the filter elementto distinguish from the impervious end enclosures thereof and also fromthe vast and/or microscopic filtering surfaces and interstices in thebody 15 of the filter element 6. Often the body or actual filteringcomponents of the element are enclosed or wrapped in paper or metalliccases 10 having perforations. 11, FIGURES 2 and 1, in which event thesuperficial pervious exterior surface of the element, as the term ishereemployed, would substantially correspond to the cylindrical surface ofthe perforate casing 10 of the element.

Whether or not the shell and element takes some or all the forms andcharacteristics used for illustration herein, the general relation ofthe element disposed Within the shell with a space for oil to flowwithin the shell and around the element to find ingress to the filteringinterstices of the body of the element is compatible with the practiceand operation of my invention.

In the form of my invention illustrated in FIGURE 1 I prefer to disposea thin, flexible somewhat resilient, perforate sheet of metallicmagnesium, or magnesiumaluminum alloy of low aluminum content, 13 in thespace inlet 4 and radially spaced at least in part from the exteriorcylindrical surface of the element 6 as well as from the interior of theshell 1 so that some or all the oil and entrained acids flowing into thefilter element will wash and flow over, around and/or upon, through andalong the surfaces of the sheet, its edges and perforations. Thisprovides a large and long wetting contact with surfaces of the sheet andaffords much opportunity for the acids to spend themselves in reactionwith the magnesium and be removed from the oil stream thereby. Based onpresent experience and the practicability of rolling and workingmagnesium in'sheet form it has been found practicable employ amagnesium-aluminum alloy of about 94-96% magnesium and 4-6% aluminum,

- the aluminum not deleteriously detracting from the acid reactivequality of the alloy and resilience, working qualities and orcommercially pure magnesium.

For one advantageous form and practice of my invention the sheet orinsert 13 may be formed about post-card size 3 /24 x 5%" x .01 to .020"and perforated preferably'as shown in FIGURE 3 with many 5 to holes 14and preferably also lightly and altergiving the sheets better cheapnessthan pure nately and oppositely dimpled as at 15, FIGURE 4, so

that the raised convexity of the dimples taken with the resilience ofthe sheet tend to space the main surfaces of the sheet from the shelland filter element and limit direct contact with the parts to the raisedbacks of the dimples, FIGURE 2. Using as many as 72 perforations of /8"diameter reduces the whole surface area less than one square inch sothat the whole surface area of both sides of the sheet of the sizementioned is about 35 square inches. Taking conventional filter elementsto run between about 3 /2 inches to inches in diameter and from about 4inches to 6- /2 inches in length, and regardcylindrical surface as theoil entering superficial area of the element, an acid-hungry sheet madeonly 3%" x 5 /2 provides surface areaequal to about A to /3 thesuperficial exterior area of large elements and nearly the same as thesuperficial exterior area of small elements. The volume of my sheet inits preferred form and size is but about .179 to .358 cubic W the oilenters at the end and flows over one of the end element, see FIGURE 2.While ease of length of the element (between 4 inch, whence its surfaceto volume ratio is between about :1 and 200:1.

I do not, of course, disclaim sheets of different size, form, thickness,material or location in or near the filter so long as my teaching as awhole and the principles of my invention are followed and enjoyed. Forexample, changesin the thickness of the sheet 13 without other changetends to depart from my present preference thus: Thicker sheets, whileeasier to roll at the rolling mill and while providing more metal, arecorrespondingly less flexible and require noticeably more manual effortto be curved to the approximate radius of the filter bending largelyconcerns the ease of installation of the sheet into the filter, thesheet if not easily bendable and lightly resilient when curved about asshown in FIGURE 2 might tend to exert enough more than a most desirableresilient lateral thrust on the element and tend to mitigate againsteasy and correct sealing of the end openings of the passage 9 or disturbthe most desirable and facile alignment of the element in the shell whenthe element and sheet are being inserted in the shell. Thinner sheetstend naturally to be expended more rapidly and require more frequentreplacement. Present experience suggests the preferred thickness for thebalance of convenience of safe and easy installation with desirableselfsupporting resilience of the sheet tending to locate it near the oilinlet. Larger sheets while practicable and not undesirable as will morefully appear below, tend to lack universality of easy insertability intofilters of nearly all presently used sizes. Smaller sheets wouldnaturally tend to be consumed more rapidly. Materials other thanmagnesium or high magnesium alloys that are highly reactive to the kindsof deleterious acids formed in engines, or which otherwise intrude intolubricating oils, such as zinc, for example, may serve the purposes ofmy invention, albeit zinc reacts more slowly to some or all such acidsand is therefore, as presently advised, less desirable than magnesium.

In FIGURE 5 it is suggested that the sheet or insert 13 may be curvedabout its long axis and longitudinally aligned and used with the filterelement 6 when the end closures or overhanging end closures) equals orexceeds the length of the reactant sheet. Such is a good disposition ofthe sheet particularly in the styles and forms of filters having no sideinlet for oil, but wherein the oil enters the shell, not shown in FIGURE5, all around the periphery of one of the ends of the element. 7 p

A modified form of my invention is also suggested in FIGURE 5,particularly for the forms of filters wherein closures of the elementbefore entering the element. Assuming the place of oil entry of such afilter is at the top as :viewed in FIGURE 5, the acid reactant sheet 13amay take disc form with a central aperture to accommodate the oilexhaust passage 9 and with its periphery corresponding to the peripheryof the closure, and be placed upon and overlie the end closure to bewashed by all the oil and acid entering the filter. For convenience ofillustration, the disc-like sheet 13a is shown in space above the upperclosure preliminary to being placed thereon. The sheet 13a may be usedalone, or with the sheet 13. The disc 13a may with advantage also havedimples and small perforations, not shown, to space the disc from theclosure and induce wetting of the lower surface adjacent the closure asWell as the upper surface. Unless the diameter of the element andclosure is great in relation to the length of the element the ratio ofthe surface area of the disc to the superficial exposed pervious area ofthe element will be smaller than I believe to be most desirable per se,but this possible lack tends to be offset by the ad vantage of positionin relation to the entering oil stream. The disc 13a being used in flatform may be thicker than the sheet 13 since considerations of resilienceand fiexibility as effecting alignment and sealing of the element in thefilter are not involved with use of the disc 13a.

Another modified form of my invention comprises that all or part of theperforate cylindrical casing of the filter element 6, or of any filterelement having, or desirably susceptible of having, a casingcorresponding to the easing 10, be made of acid-hungry sheet metal ormaterial and thus be similarly exposed to the oil entrained acids withlike or substantially identical operation, advantage and results as mypreferred form. Limitations or precautions in this form of my inventionpresently 'occur to me thus: The filter element should not be dependenton the structural strength of the casing for sealing off the oil streamor for its correct flow through the filtering body of the element if thecasing is made wholly of expendable material without risking theefliciency of the filter as the casing is consumed by the acid withwhich it reacts. Similarly the life of necessarily correspond to theuseful life of filter body as a filter, depending, inter alia, on therate of acid formation in any given engine. For practical purposeshowever, the prompt and continuous neutralization of acid and consequentinhibition of acid build-up in the engine oil such that consumption ofthe casing would measure a worth-while useful life of the whole element.Should the whole casing 10 of the filter element be made of acidreactant material, it would provide reactant surface area equal tosubstantially 200% of the superficial pervious oilentering area of thefilter body: A thing desirable per se, and as presently advised, a thingwhich would give an extraordinarily long, useful life to the filter bodyas a filter compared with the currently accepted life span of suchbodies. Among other things, my invention in all forms gives added lifeto all filter elements that are subject to deterioration from filteringoil with entrained acids by virtue of reducing and/ or substantiallyeliminating such acids from the oil stream.

It may also be convenient to practice my inventionby attaching a sheetof highly acid-reactant metal substantially corresponding to the sheet13 to the casing 19 of the filter shell as at the time and place ofmanufacture of the filter element, assuming the casing 10 according toprior practice is made of paper or not highly acid-reactant material. Inthis form of my invention better practice suggests that the reactantsheet be attached exteriorly of the casing to appear much as shown inFIGURES or 5, the perforations of the reactant sheet be fairly alignedwith the perforations of the casing, the dimpling of sheet be retainedor increased, and the attaching done not too snuggly, as with lightstaples, adjacent the dimples so that the sheet will be largely relievedfrom tight surface contact with the casing and tend to be wetted on itsinterior as well as exterior surface by oil and oil entrained acids.This form of my invention facilitates the use of thicker reactantsheets, if desired; the light, resilient flexibility mentioned asdesirable in the sheet 13 when used as a separate insert, not having thesame pertinence where the reactant sheet is attached to the elementbefore both are inserted into the shell together.

Reference to conventional forms of replaceable filter elements is notintended to suggest any lack of advantage or utility of my invention infilters having so-called permanent filter elements, my teaching andpreference comprehending the latter form of filter elements as well asthe former. Nor need the specific size and shape of the filter elementin relation to the shell detract from the advantage or impair theutility of my invention so long as opportunity is afforded for theacid-hungry metal to be wetted by the oil-entrained acids to neutralizethe latter in the oil stream in its path of movement near and toward thefiltering body. Nor is my invention essentially more or less compatiblewith by-pass type filters than so-called full-flow filters, except asthe latter perhaps tend to take better advantage of my invention bybringing more of the an acid reactant casing would not oil more often towetting contact with the acid-reactant sheet. In all forms of myinvention the freedom of fiow of oil, and/ or acid-bearing oil, along,past, around and/ or through the reactant metal sheet promotes thedesired acid neutralizing action quite consistently with the freedom offlow of oil to the filter element and/ or through the filter element.Sludge inhibition alone as induced by my invention is an especial boonto full-flow filters.

In the use and operation of my invention, oil-entrained acids arebrought to wetting and reacting contact with the exposed surface orsurfaces of the acid-reactant sheet and form insoluble metal-acid saltsthat tend to be washed, erroded or corroded off the sheet whence theyeither fall out of the oil stream to the bottom of the filter shell orare mechanically filtered out of the stream in and by the filter elementor the filtering body or parts thereof. Oil leaving the filter is thusfreed from both acid and the products of the acid reaction with thereactant sheet. The operation of my invention includes the consumptionand expenditure of the acid reactant sheet metal and the consequentdeterioration and disintegration of the sheet which on the one handmeasures the success of the operation, and on the other hand measuresthe coaction of the filter element in its role of removing the metalacid salts, as well as discreet particles and fragments of the sheet,which are formed in the course of disintegration and consumption of thesheet, from the oil stream and from the engine. As the filter bodystrains out discreet particles of the reactant metal, these particlesstill and necessarily lie in the oil stream passing through the filterand still react with acid borne thereby. Therefore, a secondary anduseful mode of operation of my invention comes into play even as thereactant metal loses its initial sheet form and changes to fragmentaryor discreet particle form, tending, incidentally, to increase thesurface to volume ratio of the reactant metal. And this same secondarymode of operation persists in kind though perhaps not in like degreewhether or not all or part of the particles or fragments of the reactantmetal are carried to the interstices of the filter body or are gatheredby gravity in the shell since their presence in the filter, wherever itmay be in the path or in part of the path of the oil-borne acids,permits their useful reaction therewith. As a practical matter theinsertion of a second new and pristine reactant sheet before the firstsheet is consumed beyond recognition as a sheet, and without removingthe remnants of the first sheet nor necessarily cleaning or replacingthe filter element, so long as the element is functioningadvantageously, is a practicable way of enjoying my invention and bothits primary and secondary modes of operation as above described.

When the reactant sheet 13 or 13a is or can be located in the filterimmediately adjacent the oil inlet and in the path of all the oil andacids entering the filter as I prefer, then naturally and advantageouslyall the acids tend to have immediate opportunity of contact, and/orturbulent scrubbing contact, with the reactant metal before reaching thefilter element. As a practical matter, only a fraction of theoil-entrained acids (literally dilute acids) need be neutralized everypass of the oil and acids over and near the reactant metal to maintainan advantageous relatively acid-free condition of the lubricant andprevent build-up of the acid content above a substantially innocuousminimum. Should a droplet of oil carrying a few molecules of acid passthrough the engine and filter a number of times without losing the acidmolecules, the law of probability, taken with the greater acid hunger ofthe magnesium metal and the lesser acid hunger of the other metals ofthe engine and the continuous exposure of the large magnesium surface tothe oil stream, makes it a near certainty that the acid will react withthe magnesium before reacting with anything else, and thereforeliterally prevent acid injury to the engine. Similarly as the magnesiumhas a great afiinity for acid relative to the aihnity of the lubricantfor acids, the reaction of acid with the magnesium will tend to precede,ergo prevent, sludge or varnish-forming reactions between the acid andthe lubricant. It therefore follows that the utility of my inventionpersists in kind and substance when the reactant sheet is disposed inthe filter remotely from the oil inlet as suggested in the dotted line23, FIGURE 2, since at least much of the oil stream entering the elementnear the sheet washes the sheet, and all the'oil in its continuous cycleof circulation and remixing in the engine tends to make frequent contactwith the reactant sheet for appreciable lengths of time whenever theengine is operating.

In all forms of my invention the acid-bearing oils are brought toextensive surface-wetting contact with acidhungry material in formhaving a high surface to volume ratio to promote opportunity for acidneutralizing reaction between the acid and the acid-hungry reactantmaterial, and, as I believe, the engine is not only protected frominjury from acids but is also protected from the products and etfects ofthe acid reaction with the oil and with the expendable material. Viewedas a method, my invention spreads the oil stream with its acid b rdeninto a form corresponding to the form and extent of the acid-hungrymaterial to promote acid neutralizing reactions preferably immediatelyprior to the filtering of the oil and/or the oil and the products andeffects of the neutralizing reaction.

Changes, improvements and modifications of and upon the forms andembodiments of my invention hereinabove specifically illustrated anddescribed will occur to those skilled in the art without departing fromthe spirit and substance of the principles of my invention or theteaching hereof, and therefore I do not desire to be limited in thescope and eifect of my patent to the forms herein specifically disclosednor in any manner inconsistent with the progress by which my inventionhas promoted the art.

I claim:

1. In an oil filter the combination of a filter shell having an innercylindrical surface, a filter element disposed in said shell with anannular space between the inside of the shell and the exterior of thefilter element, and an expendable reactant for deleterious constituentsof internal com- 8 bustion engine oil removably inserted in said annularspace between the interior surface of said oil filter shell and theexterior of said filter element without deleteriously impairing the flowof oil through the fi ter, said reactant comprising a thin, bendable,resilient, perforate sheet having exposed surfaces reactant with saidconstituents of engine oil and having thickness not substantiallygreater than about A the radial dimension of said space, widthappreciably less than the axial length of said space but more than onehundred times the thickness of the sheet, and length greater than widthbut less than the circumferential length of said space, and having aratio of surface to volume not substantially less than about :1, andhaving a surface area reactant to said constituents equal to frombetween about A to all the superficial area of said filter element, saidsheet being manually bendable to a curvature of radius similar to butgreater than the interior of said filter shell and having resiliencewhen constrained to enter said annular space and engaging said shellfrictionally and resiliently at the ends of the sheet on one side andengaging the filter element frictionally and resiliently in the middleof said sheet on the other side and tending to space itself otherwisefrom both said shell and said element.

2. The combination of claim 1 in which the reactant comprising saidsheet has alternate, oppositely facing, spaced raised portions oflimited area and disposed in the middle and at the ends of the sheet onboth sides of the sheet and tending to space all but the proximateraised portions of the sheet from contact with said shell and element atthe middle and ends of the sheet respectively.

References Cited in the file of this patent UNITED STATES PATENTS1,752,050 Young Mar. 25, 1930 2,685,565 Jones et a1 Aug. 3, 19542,785,805 Hough Mar. 19, 1957 FOREIGN PATENTS 530,498 Great Britain Dec.12, 1940

